diff options
| author | Johannes Berg | 2020-12-05 21:50:18 +0100 |
|---|---|---|
| committer | Richard Weinberger | 2020-12-13 22:38:06 +0100 |
| commit | ef4459a6da0955b533ebfc97a7d756ac090f50c9 (patch) | |
| tree | 5c1153080467c99b2f60942757f644d38338319b /arch/um/os-Linux | |
| parent | 963285b0b47a1b8e1dfa5481717855a7057ccec6 (diff) | |
um: allocate a guard page to helper threads
We've been running into stack overflows in helper threads
corrupting memory (e.g. because somebody put printf() or
os_info() there), so to avoid those causing hard-to-debug
issues later on, allocate a guard page for helper thread
stacks and mark it read-only.
Unfortunately, the crash dump at that point is useless as
the stack tracer will try to backtrace the *kernel* thread,
not the helper thread, but at least we don't survive to a
random issue caused by corruption.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/os-Linux')
| -rw-r--r-- | arch/um/os-Linux/helper.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index 9fa6e4187d4f..feb48d796e00 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -45,7 +45,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv) unsigned long stack, sp; int pid, fds[2], ret, n; - stack = alloc_stack(0, __cant_sleep()); + stack = alloc_stack(__cant_sleep()); if (stack == 0) return -ENOMEM; @@ -116,7 +116,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags, unsigned long stack, sp; int pid, status, err; - stack = alloc_stack(0, __cant_sleep()); + stack = alloc_stack(__cant_sleep()); if (stack == 0) return -ENOMEM; |